共查询到20条相似文献,搜索用时 15 毫秒
1.
Man D He W Sze KH Gong K Smith DK Zhu G Ip NY 《The Journal of biological chemistry》2003,278(26):23285-23294
The functional receptor complex of ciliary neurotrophic factor (CNTF), a member of the gp130 family of cytokines, is composed of CNTF, the CNTF receptor alpha (CNTFR), gp130, and the leukemia inhibitory factor receptor (LIFR). However, the nature of the receptor-mediated interactions in this complex has not yet been resolved. To address this issue we have determined the solution structure of the C-terminal or BC domain of CNTFR and studied the interactions of CNTFR with LIFR and gp130. We reported previously that the membrane distal cytokine-binding domain (CBD1) of LIFR could interact in vitro with soluble CNTFR (sCNTFR) in the absence of CNTF. Here we show that the CBD of human gp130 can also bind in vitro to sCNTFR in the absence of CNTF. In addition, the gp130 CBD could compete with the LIFR CBD1 for the binding of sCNTFR. Substitution of residues in the gp130 CBD, the LIFR CBD1, and the CNTFR BC domain that are expected to be involved in receptor-receptor interactions significantly reduced their interactions. An NMR chemical shift perturbation study of the interaction between the BC domains of CNTFR and gp130 further mapped the interaction surface. These data suggest that both the gp130 CBD and the LIFR CBD1 interact with CNTFR in a similar way and provide insights into the nature of the CNTF receptor complex. 相似文献
2.
Plun-Favreau H Elson G Chabbert M Froger J deLapeyrière O Lelièvre E Guillet C Hermann J Gauchat JF Gascan H Chevalier S 《The EMBO journal》2001,20(7):1692-1703
Ciliary neurotrophic factor (CNTF) is involved in the survival of a number of different neural cell types, including motor neurons. CNTF functional responses are mediated through a tripartite membrane receptor composed of two signalling receptor chains, gp130 and the leukaemia inhibitory factor receptor (LIFR), associated with a non-signalling CNTF binding receptor alpha component (CNTFR). CNTFR-deficient mice show profound neuronal deficits at birth, leading to a lethal phenotype. In contrast, inactivation of the CNTF gene leads only to a slight muscle weakness, mainly during adulthood, suggesting that CNTFR binds to a second ligand that is important for development. Modelling studies of the interleukin-6 family member cardiotrophin-like cytokine (CLC) revealed structural similarities with CNTF, including the conservation of a site I domain involved in binding to CNTFR. Co-expression of CLC and CNTFR in mammalian cells generates a secreted composite cytokine, displaying activities on cells expressing the gp130-LIFR complex on their surface. Correspondingly, CLC-CNTFR activates gp130, LIFR and STAT3 signalling components, and enhances motor neuron survival. Together, these observations demonstrate that CNTFR induces the secretion of CLC, as well as mediating the functional responses of CLC. 相似文献
3.
Gene expression of receptors for IL-6, LIF, and CNTF in regenerating skeletal muscles. 总被引:7,自引:0,他引:7
K Kami Y Morikawa M Sekimoto E Senba 《The journal of histochemistry and cytochemistry》2000,48(9):1203-1213
The biological actions of interleukin-6 (IL-6), leukemia inhibitory factor (LIF), and ciliary neurotrophic factor (CNTF) are mediated via respective functional receptor complexes consisting of a common signal-transducing component, gp130, and other specific receptor components, IL-6 receptor alpha (IL-6R), LIF receptor beta (LIFR), and CNTF receptor alpha (CNTFR). IL-6, LIF, and CNTF are implicated in skeletal muscle regeneration. However, the cell populations that express these receptor components in regenerating muscles are unknown. Using in situ hybridization histochemistry, we examined spatiotemporal expression patterns of gp130, IL-6R, LIFR, and CNTFR mRNAs in regenerating muscles after muscle contusion. At the early stages of regeneration (from 3 hr to Day 2 post contusion), significant signals for gp130 and LIFR mRNAs were detected in myonuclei and/or nuclei of muscle precursor cells (mpcs) and in mononuclear cells located in extracellular spaces between myofibers after muscle contusion, but IL-6R mRNA was expressed only in mononuclear cells. At Day 7 post contusion, signals for gp130, LIFR, and IL-6R mRNAs were not detected in newly formed myotubes, whereas the CNTFR mRNA level was upregulated in myotubes. These findings suggest that the upregulation of receptor subunits in distinct cell populations plays an important role in the effective regeneration of both myofibers and motor neurons. (J Histochem Cytochem 48:1203-1213, 2000) 相似文献
4.
Leukemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF) are neurally active cytokines, or neurokines. LIF signals through a receptor consisting of gp130 and the low affinity LIF receptor (LIFR), while the CNTF receptor consists of gp130, LIFR, and the low affinity CNTF receptor (CNTFR). Ser1044 of the LIFR is phosphorylated by Erk1/2 MAP kinase. Stimulation of neural cells with growth factors which strongly activate Erk1/2 decreases LIF-mediated signal transduction due to increased degradation of the LIFR as a consequence of Erk1/2-dependent phosphorylation of the receptor at Ser1044. 相似文献
5.
Schuster B Kovaleva M Sun Y Regenhard P Matthews V Grötzinger J Rose-John S Kallen KJ 《The Journal of biological chemistry》2003,278(11):9528-9535
Human ciliary neurotrophic factor (CNTF) is a neurotrophic cytokine that exerts a neuroprotective effect in multiple sclerosis and amyotrophic lateral sclerosis. Clinical application of human CNTF, however, was prevented by high toxicity at higher dosages. Human CNTF elicits cellular responses by induction of a receptor complex consisting of the CNTF alpha-receptor (CNTFR), which is not involved in signal transduction, and the beta-receptors gp130 and leukemia inhibitory factor receptor (LIFR). Previous studies with rat CNTF demonstrated that rat CNTF is unable to interact with the human interleukin-6 alpha-receptor, whereas at high concentrations, it can directly induce a signaling heterodimer of human gp130 and human LIFR in the absence of the CNTF receptor. Here, we demonstrate that human CNTF cannot directly induce a heterodimer of human gp130 and LIFR. However, human CNTF can use both the membrane-bound and the soluble human IL-6R as a substitute for its cognate alpha-receptor and thus widen the target spectrum of human CNTF. Engineering a CNTFR-specific human CNTF variant may therefore be a prerequisite to improving the safety profile of CNTF. 相似文献
6.
Lelièvre E Plun-Favreau H Chevalier S Froger J Guillet C Elson GC Gauchat JF Gascan H 《The Journal of biological chemistry》2001,276(25):22476-22484
Ciliary neurotrophic factor (CNTF) is a cytokine supporting the differentiation and survival of a number of neural cell types. Its receptor complex consists of a ligand-binding component, CNTF receptor (CNTFR), associated with two signaling receptor components, gp130 and leukemia inhibitory factor receptor (LIFR). Striking phenotypic differences between CNTF- and CNTFR-deficient mice suggest that CNTFR serves as a receptor for a second developmentally important ligand. We recently demonstrated that cardiotrophin-like cytokine (CLC) associates with the soluble orphan receptor cytokine-like factor-1 (CLF) to form a heterodimeric cytokine that displayed activities only on cells expressing the tripartite CNTF receptor on their surface. In this present study we examined the membrane binding of the CLC/CLF composite cytokine and observed a preferential interaction of the cytokine with the CNTFR subunit. Signaling pathways recruited by the CLC/CLF complex in human neuroblastoma cell lines were also analyzed in detail. The results obtained showed an activation of Janus kinases (JAK1, JAK2, and TYK2) leading to a tyrosine phosphorylation of the gp130 and LIFR. The phosphorylated signaling receptors served in turn as docking proteins for signal transducing molecules such as STAT3 and SHP-2. In vitro analysis revealed that the gp130-LIFR pathway could also stimulate the phosphatidylinositol 3-kinase and the mitogen-activated protein kinase pathways. In contrast to that reported before for CNTF, soluble CNTFR failed to promote the action CLC/CLF, and an absolute requirement of the membrane form of CNTFR was required to generate a functional response to the composite cytokine. This study reinforces the functional similarity between CNTF and the CLC/CLF composite cytokine defining the second ligand for CNTFR. 相似文献
7.
8.
Eva-Maria Wagener Matthias Aurich Samadhi Aparicio-Siegmund Doreen M. Floss Christoph Garbers Kati Breusing Bj?rn Rabe Ralf Schwanbeck Joachim Gr?tzinger Stefan Rose-John Jürgen Scheller 《The Journal of biological chemistry》2014,289(26):18442-18450
Ciliary neurotrophic factor (CNTF) is a neurotrophic factor with therapeutic potential for neurodegenerative diseases. Moreover, therapeutic application of CNTF reduced body weight in mice and humans. CNTF binds to high or low affinity receptor complexes consisting of CNTFR·gp130·LIFR or IL-6R·gp130·LIFR, respectively. Clinical studies of the CNTF derivative Axokine revealed intolerance at higher concentrations, which may rely on the low-affinity binding of CNTF to the IL-6R. Here, we aimed to generate a CNTFR-selective CNTF variant (CV). CV-1 contained the single amino acid exchange R28E. Arg28 is in close proximity to the CNTFR binding site. Using molecular modeling, we hypothesized that Arg28 might contribute to IL-6R/CNTFR plasticity of CNTF. CV-2 to CV-5 were generated by transferring parts of the CNTFR-binding site from cardiotrophin-like cytokine to CNTF. Cardiotrophin-like cytokine selectively signals via the CNTFR·gp130·LIFR complex, albeit with a much lower affinity compared with CNTF. As shown by immunoprecipitation, all CNTF variants retained the ability to bind to CNTFR. CV-1, CV-2, and CV-5, however, lost the ability to bind to IL-6R. Although all variants induced cytokine-dependent cellular proliferation and STAT3 phosphorylation via CNTFR·gp130·LIFR, only CV-3 induced STAT3 phosphorylation via IL-6R·gp130·LIFR. Quantification of CNTF-dependent proliferation of CNTFR·gp130·LIFR expressing cells indicated that only CV-1 was as biologically active as CNTF. Thus, the CNTFR-selective CV-1 will allow discriminating between CNTFR- and IL-6R-mediated effects in vivo. 相似文献
9.
10.
Ciliary neurotrophic factor (CNTF) is a member of the gp130 family of cytokines. The functional receptor complex of CNTF is composed of the CNTF receptor alpha (CNTFR), gp130 and the leukemia inhibitory factor receptor (LIFR). Three regions on CNTF have been identified as binding sites for its receptors. The ligand-receptor interactions are mediated through the cytokine binding domains (CBDs) and/or the immunoglobulin-like domains of the receptors. However, in the case of CNTF, the precise nature of the protein-protein contacts in the signaling complex has not yet been resolved. In this study, we provide the first demonstration that the membrane distal CBD (CBD1) of LIFR associates in vitro with soluble CNTFR in the absence of CNTF. Moreover, purified CBD1 partially blocks CNTF signaling, but not that of interleukin-6 or LIF, in human embryonal carcinoma cell line Ntera/D1 cells. These data raise the possibility that LIFR has the capability to form a ligand-free complex with CNTFR. 相似文献
11.
12.
Several lines of evidence suggest that ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor (LIF) are important for the survival and regeneration of axotomized motoneurons. To investigate the role of CNTF/LIF signaling in regenerative responses of motoneurons, we studied the expression of the three receptor components, CNTF receptor alpha (CNTFRalpha), LIF receptor beta (LIFRbeta), and gp130, and the activation of the STAT3 signal transduction pathway in the rat facial nucleus following peripheral nerve transection. As shown by in situ hybridization and immunoblotting, axotomy resulted in a rapid down-regulation of CNTFRalpha mRNA expression within 24 h and a concomitant massive up-regulation of LIFRbeta mRNA and protein in the lesioned motoneurons. The altered mRNA levels were maintained for 3 weeks but had returned back to control levels by 6 weeks postlesion after successful regeneration. In contrast, mRNA levels remained in the lesioned state during the 6-week period studied, when regeneration was prevented by nerve resection. Significant lesion-induced changes in gp130 mRNA levels were not detectable. Rapid (within 24 h) and sustained (for at least 5 days) activation of STAT3 in axotomized facial motoneurons was revealed by demonstrating the phosphorylation and nuclear translocation of the protein using immunocytochemistry and immunoblotting. In agreement with previous studies showing a complementary regulation of CNTF and LIF in the lesioned facial nerve, our observations on the postlesional regulation of CNTF/LIF receptor components in the facial nucleus indicate a direct and sequential action of the two neurotrophic proteins on axotomized facial motoneurons. 相似文献
13.
Rathje M Pankratova S Nielsen J Gotfryd K Bock E Berezin V 《European journal of cell biology》2011,90(12):990-999
Ciliary neurotrophic factor (CNTF) induces neuronal differentiation and promotes the survival of various neuronal cell types by binding to a receptor complex formed by CNTF receptor α (CNTFRα), gp130, and the leukemia inhibitory factor (LIF) receptor (LIFR). The CD loop-D helix region of CNTF has been suggested to be important for the cytokine interaction with LIFR. We designed a peptide, termed cintrofin, that encompasses this region. Surface plasmon resonance analysis demonstrated that cintrofin bound to LIFR and gp130, but not to CNTFRα, with apparent KD values of 35 nM and 1.1 nM, respectively. Cintrofin promoted the survival of cerebellar granule neurons (CGNs), in which cell death was induced either by potassium withdrawal or H2O2 treatment. Cintrofin induced neurite outgrowth from CGNs, and this effect was inhibited by specific antibodies against both gp130 and LIFR, indicating that these receptors are involved in the effects of cintrofin. The C-terminal part of the peptide, corresponding to the D helix region of CNTF, was shown to be essential for the neuritogenic action of the peptide. CNTF and LIF induced neurite outgrowth in CGNs plated on laminin-coated slides. On uncoated slides, CNTF and LIF had no neuritogenic effect but were able to inhibit cintrofin-induced neuronal differentiation, indicating that cintrofin and cytokines compete for the same receptors. In addition, cintrofin induced the phosphorylation of STAT3, Akt, and ERK, indicating that it exerts cell signaling properties similar to those induced by CNTF and may be a valuable survival agent with possible therapeutic potential. 相似文献
14.
Increased expression of IL-6 and LIF in the hypertrophied left ventricle of TGR(mRen2)27 and SHR rats 总被引:3,自引:0,他引:3
Cytokines from the interleukin-6 (IL-6) family have been reported to play an important synergistic role with angiotensin II in the development of pathological cardiac hypertrophy. Whether their expression pattern changes in vivo, in an angiotensin II-dependent hypertrophied myocardium has not been reported. In this study, we addressed that issue using two animal models of angiotensin II-dependent cardiac hypertrophy. Heterozygous transgenic TGR(mRen2)27 (TGR) with an overactive cardiac renin angiotensin system and the closely related spontaneously hypertensive rats (SHR) were compared to their respective control rats. The mRNA levels of IL-6, leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF) and cardiotrophin-1 (CT-1) as well as their receptor subunits, glycoprotein 130 (gp130), IL-6 receptor (IL-6R), LIFR, and CNTFR, were measured by semi-quantitative RT-PCR. The protein levels of IL-6, LIF and CT-1 were investigated by western blot. TGR and SHR both displayed significant over expression of mRNA and protein levels for IL-6 and LIF. In TGR, the increased level of LIF was accompanied by a decrease in mRNA levels for LIFR and CNTFR. In SHR, a higher level of mRNA IL-6R was observed. By contrast, the mRNA and protein levels for CT-1 and the mRNA level for gp130 did not vary in these two models. These findings suggest that IL-6 and LIF, but not CT-1, contribute to angiotensin II-dependent left ventricular hypertrophy in the two hypertensive rat models, TGR(mRen2)27 and SHR. (Mol Cell Biochem 269: 95–101, 2005) 相似文献
15.
Kallen KJ Grötzinger J Lelièvre E Vollmer P Aasland D Renné C Müllberg J Myer zum Büschenfelde KH Gascan H Rose-John S 《The Journal of biological chemistry》1999,274(17):11859-11867
Interleukin-6 (IL-6) and ciliary neurotrophic factor (CNTF) are "4-helical bundle" cytokines of the IL-6 type family of neuropoietic and hematopoietic cytokines. IL-6 signals by induction of a gp130 homodimer (e.g. IL-6), whereas CNTF and leukemia inhibitory factor (LIF) signal via a heterodimer of gp130 and LIF receptor (LIFR). Despite binding to the same receptor component (gp130) and a similar protein structure, IL-6 and CNTF share only 6% sequence identity. Using molecular modeling we defined a putative LIFR binding epitope on CNTF that consists of three distinct regions (C-terminal A-helix/N-terminal AB loop, BC loop, C-terminal CD-loop/N-terminal D-helix). A corresponding gp130-binding site on IL-6 was exchanged with this epitope. The resulting IL-6/CNTF chimera lost the capacity to signal via gp130 on cells without LIFR, but acquired the ability to signal via the gp130/LIFR heterodimer and STAT3 on responsive cells. Besides identifying a specific LIFR binding epitope on CNTF, our results suggest that receptor recognition sites of cytokines are organized as modules that are exchangeable even between cytokines with limited sequence homology. 相似文献
16.
Cross-talk among gp130 cytokines in adipocytes 总被引:3,自引:0,他引:3
Zvonic S Baugh JE Arbour-Reily P Mynatt RL Stephens JM 《The Journal of biological chemistry》2005,280(40):33856-33863
17.
Several lines of evidence suggest that ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor (LIF) are important for the survival and regeneration of axotomized motoneurons. To investigate the role of CNTF/LIF signaling in regenerative responses of motoneurons, we studied the expression of the three receptor components, CNTF receptor α (CNTFRα), LIF receptor β (LIFRβ), and gp130, and the activation of the STAT3 signal transduction pathway in the rat facial nucleus following peripheral nerve transection. As shown by in situ hybridization and immunoblotting, axotomy resulted in a rapid down‐regulation of CNTFRα mRNA expression within 24 h and a concomitant massive up‐regulation of LIFRβ mRNA and protein in the lesioned motoneurons. The altered mRNA levels were maintained for 3 weeks but had returned back to control levels by 6 weeks postlesion after successful regeneration. In contrast, mRNA levels remained in the lesioned state during the 6‐week period studied, when regeneration was prevented by nerve resection. Significant lesion‐induced changes in gp130 mRNA levels were not detectable. Rapid (within 24 h) and sustained (for at least 5 days) activation of STAT3 in axotomized facial motoneurons was revealed by demonstrating the phosphorylation and nuclear translocation of the protein using immunocytochemistry and immunoblotting. In agreement with previous studies showing a complementary regulation of CNTF and LIF in the lesioned facial nerve, our observations on the postlesional regulation of CNTF/LIF receptor components in the facial nucleus indicate a direct and sequential action of the two neurotrophic proteins on axotomized facial motoneurons. © 1999 John Wiley & Sons, Inc. J Neurobiol 41: 559–571, 1999 相似文献
18.
CNTF variants with increased biological potency and receptor selectivity define a functional site of receptor interaction. 总被引:8,自引:1,他引:7
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Human CNTF is a neurocytokine that elicits potent neurotrophic effects by activating a receptor complex composed of the ligand-specific alpha-receptor subunit (CNTFR alpha) and two signal transducing proteins, which together constitute a receptor for leukemia inhibitory factor (LIFR). At high concentrations, CNTF can also activate the LIFR and possibly other cross-reactive cytokine receptors in the absence of CNTFR alpha. To gain a better understanding of its structure-function relationships and to develop analogs with increased receptor specificity, the cytokine was submitted to affinity maturation using phage display technology. Variants with greatly increased CNTFR alpha affinity were selected from a phage-displayed library of CNTF variants carrying random amino acid substitutions in the putative D helix. Selected variants contained substitutions of the wild-type Gln167 residue, either alone or in combination with neighboring mutations. These results provide evidence for an important functional role of the mutagenized region in CNTFR alpha binding. Affinity enhancing mutations conferred to CNTF increased potency to trigger biological effects mediated by CNTFR alpha and enhanced neurotrophic activity on chicken ciliary neurons. In contrast, the same mutations did not potentiate the CNTFR alpha-independent receptor actions of CNTF. These CNTF analogs thus represent receptor-specific superagonists, which should help to elucidate the mechanisms underlying the pleiotropic actions of the neurocytokine. 相似文献
19.
I Tacken H Dahmen O Boisteau S Minvielle Y Jacques J Gr?tzinger A Küster U Horsten C Blanc F A Montero-Julian P C Heinrich G Müller-Newen 《European journal of biochemistry》1999,265(2):645-655
Interleukin-11 (IL-11) belongs to the interleukin-6 (IL-6)-type subfamily of long-chain helical cytokines including IL-6, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), oncostatin M, and cardiotrophin-1, which all share the glycoprotein gp130 as a signal transducing receptor component. IL-11 acts on cells expressing gp130 and the IL-11 receptor (IL-11R) alpha-subunit (IL-11Ralpha). The structural epitopes of IL-11 required for the recruitment of the individual receptor subunits have not yet been defined. Based on the structure of CNTF, a three-dimensional model of human IL-11 was built. Using this model, 10 surface exposed amino acid residues of IL-11 were selected for mutagenesis using analogies to the well-characterized receptor recruitment sites of IL-6, CNTF, and LIF. The respective mutants of human IL-11 were expressed as soluble fusion proteins in bacteria. Their biological activities were determined on HepG2 and Ba/F3-130-11alpha cells. Several mutants with substantially decreased bioactivity and one hyperagonistic mutant were identified and further analyzed with regard to recruitment of IL-11Ralpha and gp130. The low-activity mutant I171D still binds IL-11Ralpha but fails to recruit gp130, whereas the hyperagonistic variant R135E more efficiently engages the IL-11R subunits. The low-activity mutants R190E and L194D failed to bind to IL-11Ralpha. These findings reveal a common mechanism of receptor recruitment in the family of IL-6-type cytokines and offer considerable perspectives for the rational design of IL-11 antagonists and hyperagonists. 相似文献
20.
Felix Neugart Andrea Zappe Deborah M. Buk Inna Ziegler Monika Schumacher Ralph Bessey Carsten Tietz Jörg Wrachtrup 《生物化学与生物物理学报:生物膜》2009,1788(9):1890-1269
Ciliary neurotrophic factor (CNTF) signals via a receptor complex consisting of the specific CNTF receptor (CNTFR) and two promiscuous signal transducers, gp130 and leukemia inhibitory factor receptor (LIFR). Whereas earlier studies suggested that the signaling complex is a hexamer, more recent analyses strongly support a tetrameric structure. However, all studies so far analyzed the stoichiometry of the CNTF receptor complex in vitro and not in the context of living cells. We generated and expressed in mammalian cells acyl carrier protein-tagged versions of both CNTF and CNTFR. After labeling CNTF and CNTFR with different dyes we analyzed their diffusion behavior at the cell surface. Fluorescence (cross) correlation spectroscopy (FCS/FCCS) measurements reveal that CNTFR diffuses with a diffusion constant of about 2 × 10− 9 cm2 s− 1 independent of whether CNTF is bound or not. FCS and FCCS measurements detect the formation of receptor complexes containing at least two CNTFs and CNTFRs. In addition, we measured Förster-type fluorescence resonance energy transfer between two differently labeled CNTFs within a receptor complex indicating a distance of 5-7 nm between the two. These findings are not consistent with a tetrameric structure of the CNTFR complex suggesting that either hexamers and or even higher-order structures (e.g. an octamer containing two tetramers) are formed. 相似文献